Weighing scale



June 23, 1925 1,542,918 D. w. STUBBS WBIGHING SCALE Filed March 15. 1923 W 1 TN ESS:

INVENTOR.

Patented June 23, 1925.

UNITED STATES PATENT OFFICE.

DAVID w. s'rUBBs, OF CHICAGO, rumors, ASSIGNOR TO E. AND T. FAIRBANKS AND coMrANY, on ST. J'OHNSBUBY, vnnmon'r, A oonronarxon or VERMONT.

WEIGHIN G SCALE.

Application filed March 15, 1923. Serial No. 625,364.

, To all whom it may concern:

Be it known that I, DAVID W. SrUBBs, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and use ful Improvements in Weighing Scales, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to scales, and more particularly to high capacity scales which are adapted for installation with railway tracks to weigh cars and other heavy loads, and technically known as railroad track scales.

In common practice, the railroad track scale consists of a system of levers upon which is mounted a bridge designed to carry the car tracks. My invention concerns the connecting means between the scale levers and this bridge.

For this bridge, structural I beam girders are usually employed. These girders are nearly always more or less twisted or wind ing. This may be of minor consequence in ordinary structural work, but in scale de sign, it is assumed that these members will be straight, and itis a serious defect in railroad track scale installation if they are not. It is of vital importance that the platform bearings or girder chairs which support the bridge or platform of the scale should at all times be plumb. When in actual practice, the girders are found to be out of true, their inaccuracy must be compensated for at the point of connection to the attached scale bearing; otherwise, the vertical singularity of the twisted girder will be communicated to the bearings or girder chairs resulting in an out-of-plumb application of the load to the scale levers, producing inaccurate weights and increased strains in the bridge.

Heretofore, it has been the practice to plumb the bearings or girder chairs by forcing the I beam girders in one direction or another by means of braces or jack screws, and when in approximately proper position, holding them by forcible means, reaming or burning out a number of holes and riveting into position. This is a very laborious, uncertain and unsatisfactory method of procedure.

The object of my invention is to provide a compensating means whereby such faults as tin of having it shipped out all together knocked down and set up in the field.

Other objects and advantages will be in part apparent from and in part noted hereinafter in connection with thefollowing descriptionof the invention shown in the accompanying drawings.

In a conventional four-section railroad track scale, there are eight supporting units and for the purposes of these specifications, I have illustrated and described one of such supporting units only.

In the drawing, Fig.1 is a side elevation of one of the main lever supporting units. Fig.2 illustrates a cross section on line cm. Fig. 3 and Fi 4: illustrate my compensating means consisting of compensating key 3 and base 4.

' Referring more particularly to the illustrated embodiment of my invention, in the general lay-out, of Fig. 1, conventional main lever 1 is shown with load pivot 2, fulcrum pivot 7 and tip pivot 6. This is surmounted by the bearing or girder chair 4 having an upper surface with a contour of the same radius as the bottom of key 3 and with its bearing steel 5 resting upon bearing pivot 2 of the main lever. Resting upon the girder chair 4 are compensating keys 3 with contour shown in normal position by full lines and in exaggerated distorted position by dotted lines. Resting upon the compensating keys is a platform or bridge I beam girder 8 with its normal lower flange shown in full line and an exaggerated out-of-alignment lower flange shown in dotted lines. The top. of the platform girder supports one side of the platform or deck of the scale which is not shown.

Fig. 2 shows in section main lever 1, with load pivot 2, bearing steel 5 of girder chair, girder chair 4, compensating keys 3, girder 8, bolts 9 for securing girder to girder chair and bevel washers 10.

The same numerals of reference are used (3. cud

to in licate identical parts in all of the figures.

It will thus be seen that each supporting unit o1 a railroad track scale embodying my invention consists of main lever 1 with its pivots or knife edges; girder chair a with its bearing steel, or other form of submembers for connecting to the main lever; "two compensating blocks inserted between the girder chair and the I beam bridge gird-er; four bolts with nuts and washers; two on each side or web of I beam to secure girder to girder chair.

From the above description, the method of using and the operation of my invention will be obvious. In installing a railroad track scale, the bearings or girder chairs in each supporting unit are placed in position and plumbed, with the tops level and with the two compensating keys placed in position. The bridge I beam girder is then lowered until it nearly touches the compensating keys; the keys are adjusted to the inequalities of the bottom surface of the girder, the girder then lowered into place and secured to the bearing or girder chair by means of the four bolts, two on each side of the web of the girder. ther adjustment be needed, either at the time of installation or subsequently, it is only necessary to loosen the nuts of the bolts, tap the compensating keys into place and then tighten up the nuts.

For the purpose of illustration, I have shown and described one form of my invention as applied to a conventional type of supporting unit in a railroad track scale, but it is obvious that with slight modifications thereof, the device is capable of being materially altered and of bein applied to any type of supporting member in a railroad track scale, without departing from the spirit of the invention. It is to be understood that I do not limit myself to the particular details of construction or to the application of the invention to the particular type of supporting member illustrated and described.

Should any fur-.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a scale, in combination, a main lover, a load supporting member carried by said lever, a bridge girder operatively connected to the load supporting member, and a key interposed between the bridge girder and the load supporting member for the purpose of compensating for any inequalities therebetween, said key having a curved face contacting with said load supporting memher and said key being shilftable without displacing the relative positions of the said supporting member and said bridge girder.

2. In a scale, the combination with a main lever, of a load supporting member provided with a curved pocket, a bridge girder operatively connected to the lead supporting member, and a key interposed between the bridge girder and the load supporting mc1n- )er, said key ha ing a curved face of the same radius as the curved pocket and being; received in said pocket.

3. In a scale, the combination with a main lever, ot' a load supporting member provided with curved pockets, a bridge girder operativcly connected to the load supporting member, and keys interposed between the bridge girder and the load supporting member, said keys having curved faces oi? the same radii as the curved pockets and being received in said pockets. I

i. In a scale, the combination with a main lever, of a load supporting member provided with a curved pocket, a bridge girder operatively connected to the load supper 'ng member, and a shittable key interposed be tween the bridge girder and the load supporting member, said key having a curved face of the same radius as the curved pocket and being received in said pocket.

In testimony whereof, I afiiX my signature in the presence of two witnesses.

DAVID IV. ITUBBS. In presence of PAUL T. hhnwioii, L. R. BoYEn. 

